Digital cameras have become one of the most popular of electronic devices. In a recent year, more digital cameras were sold than traditional film cameras. Images from digital cameras can be downloaded and stored on personal computers. Digital pictures can be converted to common formats such as JPEG and sent as e-mail attachments or posted to virtual photo albums on the Internet. Video as well as still images can be captured, depending on the kind of digital camera.
Digital cameras typically capture images electronically and ultimately store the images as bits (ones and zeros) on a solid-state memory. Flash memory is the most common storage for digital cameras. Flash memory contains one or more electrically-erasable read-only-memory (EEPROM) integrated circuit chips that allow reading, writing, and block erasing.
Early digital cameras required the user to download or transfer the images from the flash memory within the digital camera to a personal computer (PC). A standard serial cable was most widely used. However, the limited transfer rate of the serial cable and the large size of the digital images made such serial downloads a patience-building experience. Serial downloads could easily take half an hour for only a few dozen images.
Digital camera manufacturers solved this problem by placing the flash memory chips on a small removable card. The flash-memory card could then be removed from the digital camera, much as film is removed from a standard camera. The flash-memory card could then be inserted into an appropriate slot in a PC, and the image files directly copied to the PC.
FIG. 1A shows a flash memory card and adapter for transferring images from a digital camera to a PC. A user takes pictures with digital camera 14 that are stored in image files on flash memory chip(s). The flash memory chip is contained in CompactFlash card 16, which can be removed from digital camera 14 by pressing a card-eject button. Thus CompactFlash card 16 contains the image files.
While some smaller hand-held computers or personal-digital-assistants (PDA) have slots that receive CompactFlash cards, most PCs do not. Laptop or notebook PCs have PC-card (earlier known as PCMCIA, Personal Computer Memory Card International Association) slots that can receive PCMCIA cards. Many functions have been placed on
PCMCIA cards, such as modems, Ethernet, flash memory, encryption keys, and even miniature hard drives.
CF-to-PCMCIA adapter 10 is a passive adapter that contains an opening that receives CompactFlash card 16. FIG. 1B shows CF-to-PCMCIA adapter 10 with CompactFlash card 16 inserted. Such CF-to-PCMCIA adapters 10 sell for as little as $5–10. CompactFlash is a trademark of SanDisk Corp. of Sunnyvale, Calif.
FIG. 1C shows a PC connected to a PCMCIA reader. Most laptop and notebook PCs contain one or two PCMCIA slots 22 that CF-to-PCMCIA adapter 10 can fit into. Then the user merely has to copy the image files from CompactFlash card 16 (not shown) to the hard disk of PC 20. Since high-speed parallel buses are used, transfer is rapid, about the same speed as accessing the hard disk. Thus a half-hour serial-cable transfer can be reduced to less than a minute with the $5 CF-to-PCMCIA adapter.
Desktop PCs usually do not have PCMCIA slots. Then PCMCIA reader 12 can be used. PCMCIA reader 12 accepts CF-to-PCMCIA adapter 10 and connects to PC 20 (not shown) through a parallel or high-speed Universal Serial Bus (USB) cable.
Multiple Flash-Card Formats
Although the CompactFlash card format is relatively small, being not much more than an inch square, other smaller cards have recently emerged. FIG. 2A illustrates various formats of flash-memory cards used with digital cameras. Many digital cameras still use CompactFlash card 16, which can be inserted into CF-to-PCMCIA adapter 10 for transfer to a PC. Other smaller, thinner formats have emerged and are used with some manufacturer's digital cameras. For example, SmartMedia card 24 is less than half an inch long, yet has enough flash memory capacity for dozens of images. SmartMedia-to-PCMCIA adapter 10′ is available commercially for about $60. The higher cost is believed to be due to a converter chip within adapter 10. Also, different adapters 10 are required for different memory capacities of SmartMedia card 24. SmartMedia is a trademark of the SSFDC Forum of Tokyo, Japan.
Other kinds of flash-memory cards that are being championed by different manufacturers include MultiMediaCard (MMC) 28 and the related Secure Digital Card (SD) 26. MMC is controlled by MultiMediaCard Association that includes SanDisk Corp., Infineon Technologies, and others, while SD is controlled by the SD Group that includes Matsushita Electric Industrial Co., SanDisk Corporation, and Toshiba Corp., among others. Another emerging form factor from Sony Corporation is Memory Stick card 18. Memory Stick has a PCMCIA/Floppy adapter while MMC has a floppy adapter.
The different physical shapes and pin arrangements of cards 24, 26, 28 and Memory Stick card 18 prevent their use in CF-to-PCMCIA adapter 10. Indeed, most of these cards 24, 26, 28 have less than a dozen pins, while CompactFlash card 16 has a larger 50-pin interface. Furthermore, serial data interfaces are used in the smaller cards 24, 26, 28 while a parallel data bus is used with CompactFlash card 16.
FIG. 2B shows a Memory Stick-to-PCMCIA adapter using an active converter chip 11. Memory Stick card 18 (not shown) fits into an opening in Memory Stick-to-PCMCIA adapter 15, allowing adapter 15 and the Memory Stick to be plugged into a standard PCMCIA slot on a PC. However, adapter 15 has an integrated circuit (IC) converter chip 11 within it. Converter chip 11 may be needed to convert the serial data format of Memory Stick card 18 to the parallel data format of a 68-pin PCMCIA slot. Inclusion of converter chip 11 in adapter 15 significantly increases the cost and complexity of adapter 15 compared to CF-to-PCMCIA adapter 10 which is a passive adapter without a converter chip.
While the advances in flash-memory card technology are useful, the many different card formats present a confusing array of interface requirements to a PC. Different adapters are needed for each of the card formats. PCMCIA card reader 12 can be replaced with other format readers, such as a SmartMedia Card reader, and even some multi-standard readers are available, such as a reader from Lexar Media that reads CompactFlash or SmartMedia in addition to PCMCIA.
The PCMCIA card interface (68-pins) has been around for a number of years and has been used extensively as an expansion slot for notebooks and other mobile computing devices. It is envisaged to use this popular interface to connect various devices such as SmartMedia, Memory Stick, MultimediaCard, Secure Digital card, Memory Stick V2 (also called the Duo), USB expansion slot, etc., to a computing system, printer, PDA or other system, which has a mating 68 pin connector.
When such adapters (68-pin or any other pin/interface based adapter) are used to interchangeably connect to the computing system, a method of storing these adapters near the slot is desired (see FIG. 2C).
FIG. 2C illustrates a conventional bay 100 for storing the adapters (front view). The bay 100 includes an interface port 102 and slots 103, 104 and 106 for storing adapters. The interface port 102 is the port to which dissimilar interfaces are connected via adapters. For example, a CompactFlash (or PCMCIA) interface can connect to a computing system, acting as the interface port for which other interfaces, such as SmartMedia, Memory Stick, Duo, USB, 1394, etc., can use adapters. The storage bay keeps all the adapters together.
In this type of bay, the upper slots are mounted right side up but the bottom slots require user to invert the media before inserting it into the slot. Since the slots are mounted on either side of a PCB (printed circuit board) the bottom slots are also very difficult to access. A new adapter for the upcoming smaller footprint Memory Stick (also called the Duo) is desired so as to mate it with 68-pin PCMCIA interface or 50-pin CompactFlash interface or any other similar interface. Therefore it is desirable to have a scheme wherein:
1. All slots are designed such that the flash media can be inserted face up into each slot.
2. There is comfortable separation space between the upper and lower row of slots.
What is desired is a universal adapter for flash-memory cards of several different formats. An adapter that accepts SmartMedia, MultiMediaCard, Secure Digital, and Memory Stick cards is desired. A flash-card reader with a single slot that accepts any format card using the adapter is desired. Special detection logic on the flash reader is desired to distinguish between the many flash-card formats. A low-cost passive adapter is desired that does not need an expensive converter chip. A multi-format reader is desired for a PC. A stand-alone flash reader is desired that can copy image files from flash cards without a PC.
What is further desired is an active adapter that can be used for interchangeably connecting different memory/memories to a device. For example, such a device could be a printer, a PDA device, or other device, which includes a slot for accepting a connector for a CompactFlash disk. It is known, for example, that many printers have a connector for a CompactFlash. Accordingly, what is needed is an active adapter, which addresses the above-identified problems.
It is also known that flash media is utilized in a variety of environments. Heretofore, the flash media is provided as a separate media to a device. In so doing, an array of different types of modules must be provided to allow for a connection to a device such as a digital camera, MP3 player or flash reader. It is desirable to provide a memory module that could be utilized with a variety of devices. The memory module must be compatible with existing standards and be capable of operating as a module.
Accordingly, what is also needed is a system and method for providing a plurality of memories to such a device without requiring multiple connectors or a controller within the memory module. The system should be cost effective, a simple modification and easily implementable into an existing device. What is further clearly needed is a controller that can work with multiple types of flash memory cards that have controllers, and also with flash memory cards that do not have controllers.
Furthermore, a controller IC, a system, and a method are needed to work with multiple types of flash memory cards that have controllers, and also with flash memory cards that do not have controllers.